1. Field of the Invention
The present invention relates to an endoscope apparatus that electrically drives bending of a bending portion of an endoscope, and a bending drive control method.
2. Description of the Related Art
Endoscopes with image pickup means and a bendable bending portion on a distal end side of an insertion portion are widely used for inspection, examination or the like of an inside of a body cavity.
Also, smooth insertion of an insertion portion into an intricately-curved body cavity such as a large intestine may require skills. For example, a transverse colon in a large intestine sags and causes difficulty in insertion of an insertion portion to a hepatic flexure side on a deep part side as it is. Therefore, in general, what is called “flip-up” is performed as an insertion procedure for removing a sag of a transverse colon to straighten the transverse colon.
For example, Japanese Patent Application Laid-Open Publication No. 2006-116289 discloses an endoscope apparatus that uses information on an insertion (curve) shape of a distal end side of an insertion portion, which is calculated based on detection of positions of position detection coils arranged in a longitudinal direction of the insertion portion, in addition to an image picked up by image pickup means provided at a distal end portion of the insertion portion, in order to facilitate smooth insertion of the insertion portion.